The present invention relates to telecommunications systems and, in particular, to communications access networks including, for example, the telephone local loop plant.
The access network interconnecting, for example, a telephone central office and terminal equipment at customer premises locations is conventionally referred to as the "local loop plant." This network is comprised, for each connection or "local loop," of a series of local loop segments extending from within the central office through various cross-connection elements to endpoints connected to the customer premises locations. In strictly-wire-pair-based arrangements, these cross-connection elements typically include the main distributing frame within the central office building; one or more feeder/distribution interfaces (FDIs), typically housed in grade-level pedestal cabinets or huts, or in subterranean vaults; and a serving terminal, typically housed in an enclosure mounted on a utility pole, or on or within a building, and serving as the point from which extend wire "drop pairs," or "drops," serving perhaps a half-dozen customers. Administrative database systems such as those known as COSMOS, LIrACS and PREMIS are used by the local telephone companies to maintain detailed data for each local loop, specifying all of its wire pairs so that telephone craftpersons can, for example, a) identify which wire pairs between any two cross-connection elements are available for use as additional local loops are added, and b) troubleshoot reported local loop failures.
The process of provisioning new wire-pair-based local loops and performing maintenance on the existing local loops is an expensive one. The principal source of expense is the labor cost associated with the need for craftpersons to make manual cross-connections in the FDIs and serving terminals, along with the travel time. In turn, a major part of this labor cost arises out of the fact that a not-insignificant portion of the administrative database data is inaccurate, leading to mistakes and re-works in the course of a) provisioning new local loops, and b) deprovisioning of no-longer-needed, existing loops. The data inaccuracies can arise in many ways. For example, incorrect data may be reported from the field, as happens when the wire pairs used to establish local loop connections are mis-reported. Or, the data may be inaccurately entered by clerks to whom the craftpersons report the data. At some point, the overall level of inaccuracy in the databases becomes so great that the telephone company has little choice but to deploy a significant amount of resources to go out, survey the entire loop plant, and correct the data.
Over time, digital loop carrier (DLC) and fiber-in-the-loop (FITL) systems have begun to replace at least a portion of the wire-pair-based local loop plant. The most advanced of such systems can obviate some of the problems described above. For example, these systems feature active cross-connection elements whose cross-connections can be controlled and kept track of remotely, and automatically, from a central provisioning system. However, problems remain. For example, there still remains the need for a database to keep track of the cross-connections thus made. Additionally, the remote provisioning capability itself brings with it the need to administer an added infrastructure-most notably the data links by which the central provisioning system communicates with the DLC and/or FITL systems. Moreover, manual data entry is still required when, for example, the capabilities and/or capacities of the various access network elements are changed.
The invention set forth in our co-pending, commonly assigned U.S. patent application entitled, "Method and Apparatus for Establishing Connections in a Communications Access Network," Ser. No. 113,496 filed of even date herewith ameliorates the above-described problems. In accordance with that invention, cross-connections between the switching office and any particular endpoint are set up on a call-by-call basis to establish a connection based on information generated from within the access network itself based on information generated from within the access network There is thus avoided the prior art's need for a centralized loop assignment database/provisioning system to keep track of manually made cross-connections or to carry out centrally controlled cross-connection administration.